Evaluation of a commercial creatine kinase screening test for malignant hyperthermia (porcine stress syndrome).

Two hundred and seven boars entering a Record of Performance Test Station at New Hamburg, Ontario were screened for susceptibility to malignant hyperthermia or the porcine stress syndrome. Screening tests included the determination of whole blood creatine kinase levels by a commercially available test using the method of bioluminescence and a halothane challenge. The validity of the bioluminescent or whole blood creatine kinase test as a screening mechanism for malignant hyperthermia was evaluated in boars in a field trial. The susceptibility of these animals to malignant hyperthermia or the porcine stress syndrome was unknown at the time of the study. It was determined in the initial field trial that 76.3% or 158 of the 207 boars tested by the bioluminescent creatine kinase screening test were stress susceptible. In contrast, only one boar (0.5%) reacted to a standard five minute halothane challenge. After further examination of the commercial screening test, little correlation was found to exist between the bioluminescent and Rosalki methods of creatine kinase determination. The coefficient of analytical variation for the bioluminescent method of creatine kinase determination ranged from 17.6% at a mean of 359 LU to 21.9% at a mean of 318 LU. Similarly, the coefficient for the Rosalki technique ranged from 7.1% at a mean of 324 U/L to 14.0% at a mean of 64 U/L. In addition, little correlation was found to exist between creatine kinase levels as determined by the bioluminescent method and outcome to the halothane or halothane/succinylcholine challenge, age of boars in weeks or percentage gain in weight.(ABSTRACT TRUNCATED AT 250 WORDS)